platform-msi: Store platform private data pointer in msi_device_data

Storing the platform private data in a MSI descriptor is sloppy at
best. The data belongs to the device and not to the descriptor.
Add a pointer to struct msi_device_data and store the pointer there.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221814.287680528@linutronix.de

drivers/base/platform-msi.c

@@ -38,9 +38,7 @@ static DEFINE_IDA(platform_msi_devid_ida);
  */
 static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
 {
-	u32 devid;
-
-	devid = desc->platform.msi_priv_data->devid;
+	u32 devid = desc->dev->msi.data->platform_data->devid;
 
 	return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.msi_index;
 }
@@ -85,11 +83,8 @@ static void platform_msi_update_dom_ops(struct msi_domain_info *info)
 static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
 {
 	struct msi_desc *desc = irq_data_get_msi_desc(data);
-	struct platform_msi_priv_data *priv_data;
-
-	priv_data = desc->platform.msi_priv_data;
 
-	priv_data->write_msg(desc, msg);
+	desc->dev->msi.data->platform_data->write_msg(desc, msg);
 }
 
 static void platform_msi_update_chip_ops(struct msi_domain_info *info)
@@ -126,9 +121,7 @@ static void platform_msi_free_descs(struct device *dev, int base, int nvec)
 }
 
 static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
-					     int nvec,
-					     struct platform_msi_priv_data *data)
-
+					     int nvec)
 {
 	struct msi_desc *desc;
 	int i, base = 0;
@@ -144,7 +137,6 @@ static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
 		if (!desc)
 			break;
 
-		desc->platform.msi_priv_data = data;
 		desc->platform.msi_index = base + i;
 		desc->irq = virq ? virq + i : 0;
 
@@ -161,11 +153,9 @@ static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
 	return 0;
 }
 
-static int platform_msi_alloc_descs(struct device *dev, int nvec,
-				    struct platform_msi_priv_data *data)
-
+static int platform_msi_alloc_descs(struct device *dev, int nvec)
 {
-	return platform_msi_alloc_descs_with_irq(dev, 0, nvec, data);
+	return platform_msi_alloc_descs_with_irq(dev, 0, nvec);
 }
 
 /**
@@ -199,8 +189,7 @@ struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
 	return domain;
 }
 
-static struct platform_msi_priv_data *
-platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
+static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
 					irq_write_msi_msg_t write_msi_msg)
 {
 	struct platform_msi_priv_data *datap;
@@ -213,41 +202,44 @@ platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
 	 * capable devices).
 	 */
 	if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
 		dev_err(dev, "Incompatible msi_domain, giving up\n");
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 	}
 
 	err = msi_setup_device_data(dev);
 	if (err)
-		return ERR_PTR(err);
+		return err;
 
-	/* Already had a helping of MSI? Greed... */
-	if (!list_empty(dev_to_msi_list(dev)))
-		return ERR_PTR(-EBUSY);
+	/* Already initialized? */
+	if (dev->msi.data->platform_data)
+		return -EBUSY;
 
 	datap = kzalloc(sizeof(*datap), GFP_KERNEL);
 	if (!datap)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
 	datap->devid = ida_simple_get(&platform_msi_devid_ida,
 				      0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
 	if (datap->devid < 0) {
 		err = datap->devid;
 		kfree(datap);
-		return ERR_PTR(err);
+		return err;
 	}
 
 	datap->write_msg = write_msi_msg;
 	datap->dev = dev;
-
-	return datap;
+	dev->msi.data->platform_data = datap;
+	return 0;
 }
 
-static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
+static void platform_msi_free_priv_data(struct device *dev)
 {
+	struct platform_msi_priv_data *data = dev->msi.data->platform_data;
+
+	dev->msi.data->platform_data = NULL;
 	ida_simple_remove(&platform_msi_devid_ida, data->devid);
 	kfree(data);
 }
@@ -264,14 +256,13 @@ static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
 int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
 				   irq_write_msi_msg_t write_msi_msg)
 {
-	struct platform_msi_priv_data *priv_data;
 	int err;
 
-	priv_data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
-	if (IS_ERR(priv_data))
-		return PTR_ERR(priv_data);
+	err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
+	if (err)
+		return err;
 
-	err = platform_msi_alloc_descs(dev, nvec, priv_data);
+	err = platform_msi_alloc_descs(dev, nvec);
 	if (err)
 		goto out_free_priv_data;
 
@@ -284,8 +275,7 @@ int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
 out_free_desc:
 	platform_msi_free_descs(dev, 0, nvec);
 out_free_priv_data:
-	platform_msi_free_priv_data(priv_data);
-
+	platform_msi_free_priv_data(dev);
 	return err;
 }
 EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
@@ -296,15 +286,9 @@ EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
  */
 void platform_msi_domain_free_irqs(struct device *dev)
 {
-	if (!list_empty(dev_to_msi_list(dev))) {
-		struct msi_desc *desc;
-
-		desc = first_msi_entry(dev);
-		platform_msi_free_priv_data(desc->platform.msi_priv_data);
-	}
-
 	msi_domain_free_irqs(dev->msi.domain, dev);
 	platform_msi_free_descs(dev, 0, MAX_DEV_MSIS);
+	platform_msi_free_priv_data(dev);
 }
 EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
 
@@ -351,10 +335,11 @@ __platform_msi_create_device_domain(struct device *dev,
 	struct irq_domain *domain;
 	int err;
 
-	data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
-	if (IS_ERR(data))
+	err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
+	if (err)
 		return NULL;
 
+	data = dev->msi.data->platform_data;
 	data->host_data = host_data;
 	domain = irq_domain_create_hierarchy(dev->msi.domain, 0,
 					     is_tree ? 0 : nvec,
@@ -372,7 +357,7 @@ __platform_msi_create_device_domain(struct device *dev,
 free_domain:
 	irq_domain_remove(domain);
 free_priv:
-	platform_msi_free_priv_data(data);
+	platform_msi_free_priv_data(dev);
 	return NULL;
 }
 
@@ -420,7 +405,7 @@ int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int vir
 	struct platform_msi_priv_data *data = domain->host_data;
 	int err;
 
-	err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs, data);
+	err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs);
 	if (err)
 		return err;
 

include/linux/msi.h

@@ -108,11 +108,9 @@ struct pci_msi_desc {
 
 /**
  * platform_msi_desc - Platform device specific msi descriptor data
- * @msi_priv_data:	Pointer to platform private data
  * @msi_index:		The index of the MSI descriptor for multi MSI
  */
 struct platform_msi_desc {
-	struct platform_msi_priv_data	*msi_priv_data;
 	u16				msi_index;
 };
 
@@ -177,10 +175,12 @@ struct msi_desc {
  * msi_device_data - MSI per device data
  * @properties:		MSI properties which are interesting to drivers
  * @attrs:		Pointer to the sysfs attribute group
+ * @platform_data:	Platform-MSI specific data
  */
 struct msi_device_data {
 	unsigned long			properties;
 	const struct attribute_group    **attrs;
+	struct platform_msi_priv_data	*platform_data;
 };
 
 int msi_setup_device_data(struct device *dev);